ABCs of the Periodic Table
by the.eye.does.not.SEE
Summary: "He'll end up learning the periodic table before he learns his ABCs." Mark and Lexie buy a very special gift for their son, and it brings back more than a few memories. Rated T, for some sexual references. Fluffity-fluffity-fluff.


**"He'll learn the periodic table before he learns his ABCs."**

_Author's Note__: So I actually had to make a concentrated effort while reading this _not _to use the names "Marcus" and "Alexandra." I suggest you guys take a look at these periodic table building blocks before you read the story, you can find a link on my profile-or a couple posts about it, if you're friends with me on LJ or on tumblr. I stumbled across them this afternoon while flipping through a catalog and kind of freaked out. I'm convinced the designed was a Mark/Lexie fan._

_Fluffiness and fluffiness ahead. Please enjoy._

_(The end is so, _so_ cheesy. I'm sorry, I really am.)_

.

"Lex…" Mark Sloan's voice drifted into their office from two rooms away.

Lexie Grey tapped her pen against her desk, still trying to sort out how she'd fit her maternity leave into her work schedule. Why did work make life impossible? "Yeah, Mark," she called back a second later, still not looking away from the calendar, "what is it?"

"I found something for the baby."

"You mean something _else _for the baby," Lexie sighed, not bothering to look over as she heard him approach from the other side of the house. This had to be the hundredth thing he'll _demand _that they just _have _to buy... And it would be as useless as every other piece of baby junk that showed up at their door, day after day. _I'm only six months along, for crying out loud._ She took a breath, and then finally looked over to him. "Alright, what is it this time, Mark?"  
He simply grinned at her exasperation, knowing she would love this particular item as much as he did. He flipped around the laptop he was holding, tipping its screen so she could see the image on the browser.

"Oh, god," she whispered, lifting a hand to cover her mouth as she got slowly to her feet. He could see her smile widen even from behind her fingertips, and it made his grin grow larger. She dropped her hand a moment later. "Buy them," she ordered, her eyes flying to his. "Buy them, buy them, you have to—oh my god. Buy them, Mark. Now."

He grinned, chuckling. "My thoughts exactly." He set down the computer beside her calendar. "And I already did."

She couldn't help but smile at his buying habits. _At least this one will be something we can all enjoy. _Her hands drifted to her protruding stomach automatically as she thought of the baby. Her husband was at her side a moment later, wrapping his arm around her waist and pressing a kiss to her temple.

"You remember that first night like I do?" He asked softly, thinking of how they began.

She grinned, looking to the floor to hide it from him. "I don't know, Mark, I was pretty drunk…"

"Oh, shut up," he muttered, bumping his hip against hers reproachfully.

She smiled, lifting her eyes to meet his. They traveled over his face, taking in the familiar and almost ever-present happiness on his face. Joy became etched into his features during this last half-year, Lexie was sure of it. She could sometimes pick out the smile lines around his mouth from all the time he spent grinning over the tiny being growing inside of her. She loved seeing those lines, though she never mentioned it to him—with the baby coming, he'd grown fond of spiraling into rants and depressions about how he'd be in his sixties by the time their baby graduated college. She'd told him time and time again that she didn't care and _wouldn't _care—it _didn't matter_… But he never listened.

After a few run-ins with such complaints, she'd realized that there was only one sure-fire solution. It had solved a lot of their problems over the years—sometimes even created new ones. It was how they'd met, and how they'd made their son. It was them.

Her eyes were full of mischief when they found his. "Do you remember your periodic table, Dr. Sloan?"

A grin spread over his face automatically, and he pulled her closer as his hands rested on her waist. "Bits and pieces here and there." She giggled when one drifted to her behind. "But maybe you can refresh me, Dr. Grey?" His blue eyes were alight with equal parts impishness and tenderness, and she melted into them and him, whispering the elements in his ear as he carried her to bed.

.

.

"He'll end up learning the periodic table before he learns his ABCs."

Mark shrugged, crossing his arms. "You know," he observed, "I don't really care."

She grinned, chuckling. "And you promised me you'd be a good dad." He elbowed her in the ribs for that, and she couldn't help but laugh. "I'm kidding," she added gently, knowing that being a father still was and would probably always be a sore spot for him. "You're a fantastic dad. Everyone knows that… especially him."

Mark didn't reply to her compliments, but then, he never replied to any compliments—not the ones that mattered. "Can you still recite them all?" He wondered a moment later, not even bothering to conceal the swift subject change.

She rolled her eyes. "_Can I, _he asks." She scoffed. "Please. Mark, how long have we been married?"

"Too damn long," he replied dryly, laughing when she smacked him. He leaned over a moment later, his hand sliding out to rest over her bottom. "Recite it to me later tonight," he murmured in her ear, "once he's asleep."

She shook her head, but he could see a smile on her face. "I can't believe that still turns you on."

"_You _turn me on," he replied, gripping her ass more firmly. She reached back for his hand and drew it around her waist, interlocking his fingers with hers. He smiled when she rested her head on his shoulder, and stepped closer so she could lean her body against his as they watched their little son play with his blocks.

He heard her murmur something under her breath a minute later. He cocked his ear, but he still couldn't make out what she was saying. "Lex?" He murmured, leaning closer. "What is it?"

She turned her head, looking at him with a bright smile. "I didn't say anything." She leaned her head back against his shoulder, but a second later, he could hear her whispering again. He was about to ask what she was saying again, to demand to know this time, when he heard her. "Boron, Carbon, Nitrogen…"

"_Lexie_." Her name escaped his mouth in a growl. She knew what that did to him, damn it. She'd found out that very first night. She found out every night.

She looked back over at him, a taunting smile playing at her lips. "You wanted to know if I could still recite it," she teased.

"And didn't you hear the _once he's asleep _portion of that request?"

She tilted her head to the side, considering. "No, I did not, actually."

He closed his eyes, biting back a groan.

"Oxygen, Fluorine, Neon…"

"Enough, Lexie."

"…Sodium, Magnesium, Aluminum, Silicon… "

"You've made your point."

"Phosphorus, Sulfur, Chlorine—"

"I said you've made your point, Lex."

She grinned saucily at him, leaning back against his waist. She rubbed her ass against his crotch before he could even think to stop her. "But have you made yours?"

His hands flew to her waist immediately, and he squeezed his eyes shut harder this time. God, he wished for nothing more than to be able to pull her tight against him, pick her up, and carry her off to bed… or to the nearest wall or table or countertop. He sighed, and instead pushed her gently away. _I can't do that anymore. _His eyes opened, and immediately found their son, obliviously playing with his little blocks on the rug in the middle of the room. It hit him then like it hit him nearly every day: _I'm a dad now. A parent. A father._ At times, he hated having to put other people before his wife.

But this was his son.

He stared at that little boy in wonder, his eyes roaming over the child's doughy face and chestnut-colored hair. Mark felt his heart constrict when his son looked up at him; he immediately recognized those chocolate-brown eyes. They were Lexie's. _Well, _he reasoned with a small smile, _he's a part of Lex. So technically I'm still putting her first._

"We'll continue this later," his wife whispered then, leaning back to kiss his neck softly before stepping away.

Mark turned to her slowly, not wanting to tear his eyes from his son yet. "Why the sudden change of heart?" He wondered.

She smiled happily at him, taking his hand. With a tug, she led them across the room towards their son. "Because of how you looked at him," she explained quietly. "I love seeing that look in your eyes. I love seeing how much you love our baby."

A gentle smile tipped up the corners of Mark Sloan's mouth. "You know how much I love him."

"It's still nice to see." She paused. "Nice enough that I'll even pass up sex for the time being to see it," she smiled.

He snorted, "Like I would've given it to you."

She just rolled her eyes, confident as ever on the subject. "Honey, please. If you are going to attempt to lie to my face, at least try something that _might _sound the littlest bit truthful."

"That _was _truthful."

She stopped walking so she could look him dead in the eye. "Mark Sloan."

"What?" He demanded to know, his voice rising a bit higher in defense. "I wouldn't have given in. I wouldn't have given it to you."

She smiled cloying at him, almost condescending in its sweetness. "Sweetheart, you've given it to me—_hard_—after a straight thirty-hour shift. Don't try to tell me you wouldn't now just 'cause we have a baby. Nothing can stop you." A happy grin spread over her face and she glanced to her watch. "And nothing stops me, either." She held it up for him to see. "He has his nap in twenty minutes."

"Lex—"

She shook her head. "No arguments. You want sex, I want sex…" She tilted her head up to look him in the eye, and her voice softened. "He'll be _asleep, _honey."

Mark's eyes flew to the toddler on the floor. He bit the inside of his lip. "He could… hear us…"

She squeezed his hand. "Then I'll be quiet."

He turned to meet her eyes slowly, a smirk spreading over his face. "I don't think that's possible for you, Little Grey."

She smiled, chuckling, and allowed that. "Then I'll stuff cotton in his ears after he's asleep and soundproof the doors." She leaned forward to peck him on the lips. "Happy now?"

"Very happy." He stepped towards her to kiss her back, deeper this time. He leaned his forehead against hers after their lips broke. "C'mon," he murmured softly, taking her other hand in his and squeezing both of hers in both of his. "Let's teach our baby the periodic table."

Lexie grinned, kissing him once more before pulling away and leading the way towards the center of the room. "I'll teach you it in twenty minutes," she whispered with a naughty grin, just before joining her son on the plush carpet they'd laid out for him to play on.

"I'm a slow learner," Mark murmured, sitting down beside her, "so I think we might need more time than one of his naps."

Lexie smiled at the floor as she rearranged a couple blocks. "Good thing he's a heavy sleeper." She paused. "I just won't wake him up this time." Her eyes met his, and neither could hold back a grin. After a moment, he turned back to the blocks he'd been rummaging with.

"Good thing," he repeated softly, already too focused on playing with the blocks. Lexie smiled; she always loved how seriously he took being a father. Every playtime he had with his son was as important as any world-class surgery he performed at work. Mark pushed a few blocks around for a couple seconds more and then leaned back. Lexie glanced at them briefly, and took a moment to read them, as he'd arranged them in a straight line—obviously a message.

_Iodine, Lutetium, Vanadium, Uranium._

He watched as her lips moved as she stared at the blocks, and frowned when she frowned. He glanced down to the letters—wasn't it obvious? There was no hidden meaning, no code. It was plain to see. It wasn't exactly spelled correctly—not letter for letter or word for word—but it was easy enough to make out… Wasn't it?

Lexie's eyes narrowed as she studied the elements again.

_Iodine, Lutetium, Vanadium, Uranium._

She bit her lower lip in concentration, running through the background of each element in her mind. When nothing of importance came up, she leaned back to get a better look at the blocks, certain she'd missed something, and then it hit her— _I Lu V U._ She couldn't help the silly grin that sprouted on her face, nor the giggle that bubbled to her lips. _I love you. _Her eyes flew to his.

"Took you long enough," Mark noted dryly, trying not to smile at the happiness in her brown eyes. "And you're supposed to be the brilliant one in this family," he grumbled.

She laughed softly, and leaned forward to cup his cheeks in her hands and kiss him. "I love you too, jerk," she whispered against his lips.

.

_Author's Note: Reviews are greatly appreciated! I hope you all liked this little one-shot :)_


End file.
